Computers and data storage have come a long way since computers were invented. Data is generated in huge volumes by innumerable individuals and companies. It is not always possible to make hard copies of all that goes on in a computer. A backup of all the data, whether it is from banks, utilities, educational institutions, businesses or personal work, is imperative. On a small scale, data can be backed up on CDs and flash drives apart from the hard disk drives. These are far more evolved than the punch cards, magnetic tapes and floppy disks used some years back.